ADS-B promises to make air traffic control easier, cheaper and in many ways safer by allowing planes to transmit their locations by radio frequency instead of depending on towers to use radar to track and coordinate them.

FORBES: Next-Gen Air Traffic Control Vulnerable To Hackers Spoofing Planes Out Of Thin Air

But Switzerland's train system is second only to Japan's for its comprehensiveness and frequency of use by locals.

BBC: Switzerland by public transport

State intervention is justified only by the chaos that would be caused by a free-for-all over the use of the frequency spectrum.

ECONOMIST: Letters